A real-world test performed by the Dutch province of Zeeland (a very windy place) confirms our earlier analysis that small windmills are a fundamentally flawed technology (test results here, pdf in Dutch). Twelve of these much hyped machines were placed in a row on an open plain (picture above). Their energy yield was measured over a period of one year (April 1, 2008 - March 31, 2009), the average wind velocity during these 12 months was 3.8 meters per second (note: update on the wind speed). Three windmills broke. Find the disappointing results of the others below.
A small windmill on your roof or in the garden is an attractive idea. Unfortunately, micro wind turbines deliver hardly enough energy to power a light bulb. Their financial payback time is much longer than their life expectancy and in urban areas they will not even deliver as much energy as was needed to produce them. Sad, but true.
Hand powered drilling tools and machines The drilling tools that appeared in the late 19th century were not only a vast improvement over earlier tools; they also have many advantages over their present-day successors, the power drills.
Pedal powered farms and factories Pedals and cranks could make an important contribution to running a post-carbon society that maintains many of the comforts of a modern life.
Firewood in the fuel tank Wood gas cars are a not-so-elegant but surprisingly efficient and ecological alternative to their petrol (gasoline) cousins, whilst their range is comparable to that of electric cars.
The Citroen 2CV: cleantech from the 1940s In spite of all the high-tech that has been squeezed into cars since then, the 2CV from 1949 is still more energy-efficient than the smallest model of the French car designer today.
Aerial ropeways: automatic cargo transport for a bargain These days, we use them almost exclusively to transport skiers and snowboarders up snow slopes, but before the 1940s, aerial ropeways were a common means of cargo transport.
The bright future of solar powered factories To power industrial processes like the making of chemicals, the smelting of metals or the production of microchips and solar panels, we need a renewable source of thermal energy.
Insulation: first the body, then the home Modern thermal underclothing offers the possibility to turn the thermostat much lower without sacrificing comfort or sex appeal.
The monster footprint of digital technology The embodied energy of the memory chip alone already exceeds the energy consumption of a laptop during its life expectancy of 3 years
The age of speed: how to reduce global fuel consumption by 75 percent Engineers treat velocity as a non-variable, while in fact it is the most powerful factor to save a really huge amount of energy - with just one stroke, at minimal cost, and without the need for new technology.
Ropes and Knots Ropes and knots are among the most ancient and useful technologies ever developed by man, predating the wheel, the axe and probably also the use of fire.
Email in the 18th century: the optical telegraph More than 200 years ago it was already possible to send messages throughout Europe and America at the speed of an aeroplane – wireless and without need for electricity.
Trolley canal boats For many centuries, canal boats were propelled by men, horses or mules on the towpath beside the water. Before diesel power took over, engineers developed several interesting methods powered by electricity: trolleyboats, floating funiculars and electric mules.
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